Republican presidential front-runner Donald Trump accused a Breitbart reporter of fabricating her accusation that his campaign manager grabbed her hard enough to leave a bruise during a campaign event.

"Perhaps she made the story up. I think that's what happened," he said of Tuesday night's alleged incident.

"I believe I was in the middle of a lot of Secret Service agents, and they all said that they never saw anything," Trump said. "And these are very honorable guys, they're fantastic people, and there were a lot of them and nobody saw anything, and to the best of my knowledge there's no pictures."

Breitbart's Michelle Fields accused Trump campaign manager Corey Lewandowski of grabbing her arm and "aggressively" yanking her aside after she questioned the candidate about affirmative action following an event in Florida.

Fields wrote an account of the incident -- which a Washington Post journalist reportedly witnessed. Politico published an audio transcript that purportedly captures the interaction and moments immediately afterward when the Washington Post reporter claims it was Lewandowski who committed the alleged assault.

CORAL GABLES, FL - MARCH 10: Republican presidential candidates, Donald Trump and Sen. Ted Cruz (R-TX), are seen during the CNN, Salem Media Group, The Washington Times Republican Presidential Primary Debate on the campus of the University of Miami on March 10, 2016 in Coral Gables, Florida. The candidates continue to campaign before the March 15th Florida primary. (Photo by Joe Raedle/Getty Images)

CORAL GABLES, FL - MARCH 10: Republican presidential candidates, Sen. Marco Rubio (R-FL), Donald Trump, Sen. Ted Cruz (R-TX), and Ohio Gov. John Kasich listen to the national anthem before the CNN, Salem Media Group, The Washington Times Republican Presidential Primary Debate on the campus of the University of Miami on March 10, 2016 in Coral Gables, Florida. The candidates continue to campaign before the March 15th Florida primary. (Photo by Joe Raedle/Getty Images)

CORAL GABLES, FL - MARCH 10: Republican presidential candidates Donald Trump and Sen. Ted Cruz (R-TX), along with Ohio Gov. John Kasich and Sen. Marco Rubio (R-FL) (not seen) listen to the national anthem before the start of the CNN, Salem Media Group, The Washington Times Republican Presidential Primary Debate on the campus of the University of Miami on March 10, 2016 in Coral Gables, Florida. The candidates continue to campaign before the March 15th Florida primary. (Photo by Joe Raedle/Getty Images)

CORAL GABLES, FL - MARCH 10: Republican presidential candidates, Sen. Marco Rubio (R-FL), Donald Trump and Sen. Ted Cruz (R-TX) are seen during the CNN, Salem Media Group, The Washington Times Republican Presidential Primary Debate on the campus of the University of Miami on March 10, 2016 in Coral Gables, Florida. The candidates continue to campaign before the March 15th Florida primary. (Photo by Joe Raedle/Getty Images)

CORAL GABLES, FL - MARCH 10: Republican presidential candidates, Donald Trump, Sen. Ted Cruz (R-TX), and Ohio Gov. John Kasich stand on stage as they arrive for the CNN, Salem Media Group, The Washington Times Republican Presidential Primary Debate on the campus of the University of Miami on March 10, 2016 in Coral Gables, Florida. The candidates continue to campaign before the March 15th Florida primary. (Photo by Joe Raedle/Getty Images)

While the Trump campaign publicly slammed the allegations, a source with knowledge of the campaign says they came as no surprise.

"Corey has always had an extremely aggressive and contentious relationship with the media," the source said. "We've known his irrational anger could be a liability but we've crossed our fingers that something over the top like this would not happen."